Oracle have a sales pitch - I've been on the end of Oracle's - that is "we'll sell it for less, we don't care, name a price we just want to hurt Red Hat."
Ubuntu ships the live patching that was developed by SUSE and Red Hat.
After Oracle acquired the company that developed ksplice and took the technology private, SUSE started to develop kGraft[1] and Red Hat started to develop kpatch[2], and these were eventually merged and upstreamed[3] into Linux.
OEL is just rebuilt RHEL.